In order to establish a new platform to manufacture micro-sized solid oxide fuel cells (SOFCs) with low operating temperatures, new design concepts, new preparation methods and new materials are being explored. Our studies in this paper are focused on the electrolyte material, and in particular gadolinia doped ceria (GDC), an electrolyte material, likely to replace the traditional yttria-stabilised zirconia (YSZ) for low temperature applications. GDC films were grown on a single crystal Si by pulsed laser deposition (PLD). The microstructure of the films as a function of growth time has been studied. We have found that the mean grain size increases with film thickness h as h(2/5), in agreement with theoretical results. (C) 2008 Elsevier B. V. All rights reserved.